Modular toy building block



FIG. 1 is a left front perspective view of a modular toy building block showing our new design;

FIG. 2 is a right rear perspective view thereof;

FIG. 3 is a front elevation view thereof, the rear elevation view being a mirror image thereof;

FIG. 4 is a left side elevation view thereof;

FIG. 5 is a right side elevation view thereof;

FIG. 6 is a top plan view thereof; and,

FIG. 7 is a bottom plan view thereof. 

CLAIM We claim the ornamental design for a modular toy building block, as shown and described. 